Left Ventricular Assist Device Therapy Research Articles

(816) - Best Practices to Manage Right Ventricular Dysfunction in Patients with Left Ventricular Assist Device Therapy

(816) - Best Practices to Manage Right Ventricular Dysfunction in Patients with Left Ventricular Assist Device Therapy

Low Mean Perfusion Pressure Indexed to Body Surface Area is a Powerful Predictor of Poor Outcomes After Heart Transplantation in Patients With High Pre-Transplant Venous Pressure: A Clinical Study With Physiological Insights From Mathematical Modelling of Biventricular Heart Failure

The deleterious consequences of chronically elevated venous pressure in patients with profound right ventricular or biventricular dysfunction are well known, including renal and hepatic dysfunction, and volume overload. The only option for these patients, if they fail optimal medical treatment, is a heart transplant, as they are not candidates for left ventricular assist device therapy. Mean perfusion pressure (MPP) is important in the outcomes of critically ill patients with high venous pressure. The question arises whether MPP is important for the outcomes of heart transplants in patients with elevated pre-transplant venous pressure. Medical management of heart failure patients with reduced ejection fraction involves lowering the systemic afterload with vasodilators while awaiting a transplant. We hypothesised that when venous pressure is elevated prior to transplant, a substantial reduction in systemic arterial elastance (Ea) through vasodilation may significantly decrease MPP, resulting in compromised end-organ function and consequent unfavourable outcomes after heart transplantation. This study aims to investigate whether a low MPP serves as a risk factor for adverse outcomes in heart transplant recipients with high venous pressure. A retrospective analysis was conducted on 250 heart transplant recipients undergoing isolated heart transplantation at a single institution from October 2012 to March 2020. Right atrial pressure (RAP) of more than 15 mmHg was considered high. Additionally, Ea calculated as the ratio of end-systolic pressure to stroke volume, and MPP calculated as the difference between mean arterial pressure and RAP were considered in our analysis. The outcomes of transplantation were measured in terms of 90-day mortality and survival up to 7 years. High RAP was a significant risk factor for short-term and medium-term survival if Ea was low (<2.7 mmHg/mL, the median value). This group had 39.39% in-hospital mortality compared to 14.49% for RAP<15 mmHg (p∼0.005). When Ea was high, this difference in survival was not evident: 8% for RAP<15 mmHg vs 4.8% for RAP>15 mmHg (p∼0.550). This effect was mediated through a lower MPP, and the mortality due to lower MPP increased strikingly with higher body surface area (BSA). A negative correlation was observed between MPP indexed to BSA (MPPI) and the Model for End-Stage Liver Disease score (r∼-0.3580, p<0.0001) as well as creatinine (r∼-0.3551, p<0.0001). MPPI less than 40 mmHg/m2 was associated with poorer short-term (23.2% for MPPI<40 mmHg/m2 vs 7.1% for MPPI>40 mmHg/m2, p∼0.001) and medium-term survival. The impact of high RAP and low Ea on survival was evident even on medium-term follow-up; only 30% survival at 7 years follow-up for high RAP and low Ea vs 75% for RAP<15 mmHg (p∼0.0033). The acceptable blood pressure during vasodilator therapy in patients with high RAP needs to be higher, especially in those with higher BSA. MPPI less than 40 mmHg/m2 is a risk factor for survival, in the short and medium-term, after heart transplantation.

Patients’ and physicians’ beliefs and attitudes towards integrating personalized risk estimates into patient education about left ventricular assist device therapy

BackgroundPersonalized risk (PR) estimates may enhance clinical decision making and risk communication by providing individualized estimates of patient outcomes. We explored stakeholder attitudes toward the utility, acceptability, usefulness and best-practices for integrating PR estimates into patient education and decision making about Left Ventricular Assist Device (LVAD). Methods and ResultsAs part of a 5-year multi-institutional AHRQ project, we conducted 40 interviews with stakeholders (physicians, nurse coordinators, patients, and caregivers), analyzed using Thematic Content Analysis. All stakeholder groups voiced positive views towards integrating PR in decision making. Patients, caregivers and coordinators emphasized that PR can help to better understand a patient’s condition and risks, prepare mentally and logistically for likely outcomes, and meaningfully engage in decision making. Physicians felt it can improve their decision making by enhancing insight into outcomes, enhance tailored pre-emptive care, increase confidence in decisions, and reduce bias and subjectivity. All stakeholder groups also raised concerns about accuracy, representativeness and relevance of algorithms; predictive uncertainty; utility in relation to physician's expertise; potential negative reactions among patients; and overreliance. ConclusionStakeholders are optimistic about integrating PR into clinical decision making, but acceptability depends on prospectively demonstrating accuracy, relevance and evidence that benefits of PR outweigh potential negative impacts on decision making quality.

Trust criteria for artificial intelligence in health: normative and epistemic considerations

Rapid advancements in artificial intelligence and machine learning (AI/ML) in healthcare raise pressing questions about how much users should trust AI/ML systems, particularly for high stakes clinical decision-making. Ensuring that...

Revisiting Pulmonary Hypertension in the Era of Temporary Mechanical Circulatory Support – Literature Review and Case-Based Discussion

Pulmonary arterial hypertension (PAH) is characterized by persistently increased pressure in the pulmonary arteries. New defining criteria for the different hemodynamic types of pulmonary hypertension (PH) that occur with left heart disease have been proposed by the task force on PH. After consideration of the changes in the general definition of PH in left heart disease, the proposed hemodynamic definition was: (1) isolated postcapillary PH: pulmonary artery wedge pressure >15 mm Hg and mean pulmonary arterial pressure (mPAP) >20 mm Hg and pulmonary vascular resistance (PVR) <3 Woods units (WU); and (2) combined post- and precapillary PH: pulmonary artery wedge pressure >15 mm Hg, mPAP >20 mm Hg, and PVR ≥3 WU. Secondary PH is initially reversible, but eventually, it can become fixed because of the remodeling process of the pulmonary vascular system. Limitations in defining both the time for and amount of reversibility lack clarity. We discuss a case of PH as a framework to better understand these key principles in addressing patients' candidacy for heart or heart-lung transplantation. We performed a literature search for all available contemporary data with the following terms: "pulmonary hypertension," "reversal," "Impella 5.5," "temporary mechanical support," and "LVAD" using the National Library of Medicine - PubMed and PubMed Central between 2019 and 2023. A total of 14 published papers were found with these search. From these, 3 addressed the issue of PH and reversibility in the setting of LHD after durable LVAD placement. No papers were found using Impella 5.5 and PH during this timeframe. Given the paucity of data in the field regarding temporary mechanical circulatory support and pulmonary hypertension, we present a case-based discussion to guide the reader in understanding the potential impact of this method in patients with WHO Class 2 Pulmonary hypertension. A 49-year-old woman with a medical history of acute on chronic biventricular systolic and diastolic heart failure, American College of Cardiology stage D, Stevenson profile C, New York Heart Association class IV (ejection fraction 18%) secondary to nonischemic cardiomyopathy after cardiac resynchronization therapy, pulmonary hypertension, bilateral deep vein thrombosis, and segmental pulmonary embolism presented for heart transplant evaluation. Her cardiac output and central hemodynamics were measured, and she was found to have a pulmonary artery (PA) pressure of 78/38 with a mean PA pressure of 51, pulmonary capillary wedge pressure (PCWP) 30, transpulmonary pressure gradient (TPG) 21, thermodilution cardiac output (CO) 3.35 L/min, and cardiac input (CI) 1.75 L/min/m2. Her PVR was 6.2 WU. Provocative pharmacologic testing for reversibility of PH was performed using sodium nitroprusside, which resulted in a blood pressure of 83/57 (92), heart rate 92/min, and PA pressure of 71/31, with a mean PA pressure of 44 PCWP 22, TPG 22, CO 4.8 L/min, and CI of 2.48 L/min/m2 with a PVR of 4.5 WU. Following this, the patient underwent Impella 5.5 placement through the right axillary artery to optimize afterload reduction and improve end-organ perfusion. Post-Impella hemodynamics on milrinone 0.5 mcg/kg/min demonstrated the following: blood pressure 90/66 (74), heart rate 53/min, and PA pressure of 56/29, with a mean PA pressure of 38, PCWP 24, TPG 14, CO 6 L/min, and CI of 2.9 L/min/m2 with a PVR of 2.3 WU. Left ventricular assist device support with Impella 5.5 is associated with a reduction in mPAP and PVR over weeks to months and thus plays a crucial role as a bridge to transplant. Our case and this review highlights the characteristics of PH resulting from heart failure with reduced ejection fraction and discusses the important clinical issues related to the treatment of these patients. We have shown that left ventricular assist device therapy with Impella 5.5 can effectively reduce left-sided filling pressures and lead to PH improvement. We demonstrate the potential benefits of Impella 5.5 in the management of patients with WHO 2 PH and cardiogenic shock with impaired hemodynamics.

Abstract 13703: Left Ventricular Assist Device Therapy in “Cold and Dry” Patients

Introduction: Patients who suffer from end-stage HF and have low PCWP are referred to as “cold and dry” patients and are an understudied minority, where the benefit derived from LVAD therapy is unclear. We therefore conducted a retrospective analysis to evaluate functional outcomes and quality of life after LVAD in patients with low versus high PCWP on pre-LVAD hemodynamics. Methods: Adults receiving LVADs between 2006 and 2017 were identified from the INTERMACS database. Outcomes include assessment of functional status with 6-minute walk test (6MWT) distance and quality of life measures, with KCCQ and EuroQol questionnaire scores pre- and post-LVAD, stratified by pre-LVAD PCWP. Median follow up was 364±41 days. Results: Study sample comprised 10310 patients who received LVAD from 2006 to 2017. Mean age was 57 ± 13, 8113 (79%) were male, and the mean PCWP prior to LVAD implantation was 25 ± 9.19 mmHg. The patients were separated into a high (PCWP &gt;15 mmHg) and a low (PCWP&lt;15 mmHg) group based on pre-LVAD hemodynamics. For patients with PCWP &lt;15 mmHg, mean age was 58.1±12.4, 1191 (74%) were males, LVEDD was 6.7±1 cm, and mean PCWP was 11±3.2 mmHg (Table 1). When compared to patients with high PWCP, those with a PCWP &lt;15 mmHg showed less improvement in quality of life questionnaire scores, including EuroQol (+0.11 vs +0.17, p=0.001) and KCCQ (+26 vs +31, p=0.03), and functional capacity with 6MWT distance (+194 feet vs +340 feet, p=0.02) after LVAD (Figure 1). Conclusions: In patients with end-stage HF and low PCWP, LVADs are associated with less improvement in functional capacity and quality of life when compared to patients with high PCWP.

Design of a hybrid left ventricular assist device with a new wireless charging system.

The objective of this study was to design a new wireless left ventricular assist device (LVAD) that can be charged without using a conventional transcutaneous energy transfer system (TETS). Our new wireless LVAD was a hybrid pump operating in two different modes: magnetic and electric modes. The pump was driven wirelessly by extracorporeal rotating magnets in magnetic mode, whereas it was driven by electricity provided by an intracorporeal battery in electric mode. A magnetic torque transmission system was introduced to wirelessly transmit torque to the pump impeller. The intracorporeal battery was charged in magnetic mode making use of electromagnetic coils as a generator, whereas the coils were used as a motor in electric mode. To demonstrate the feasibility of our system, we conducted a bench-top durability test for 1 week. Our hybrid pump had shown sufficient pump performance as a LVAD, with a head pressure of approximately 80 mm Hg and a flow volume of 5.0 L/min, for 1 week. The intracorporeal battery was wirelessly charged enough to power electric mode for 2.5 h a day throughout the 1-week durability test. Our hybrid wireless LVAD system demonstrated the possibility of a wireless LVAD and has the potential to reduce medical complications of LVAD therapy.

Contemporary Left Ventricular Assist Device Therapy as a Bridge or Alternative to Transplantation.

Left ventricular assist devices (LVADs), which were introduced as a bridge to heart transplantation, are now an established alternative to heart transplantation (HT) for patients with advanced heart failure. These devices have undergone significant technological advancements over the years, and contemporary LVADs prolong life substantially in patients dependent on inotropic therapy or in those with severe ambulatory advanced heart failure with a median survival that exceeds 5 y, and most patients benefit from a doubling in functional capacity, even among those intended as destination therapy because of ineligibility for transplantation. Other intended goals for LVAD implantation consist of (1) bridge to remission or recovery and (2) bridge to transplant or candidacy for transplant. In the former situation, few selected patients underwent LVAD implantation, facilitating myocardial remission to recovery that allowed explantation. Among those bridged to transplantation, survival in the intended goal was excellent, with 80% success at 5 y (with a 50% rate of transplantation). In this review, we provide a brief historical background on the evolution of LVADs and discuss outcomes with contemporary pumps, immunological and infection-related impact of such devices, impact of bridging in HT, and use of devices for facilitating myocardial recovery and remission. Furthermore, we discuss implications of HT allocation policies, with a specific focus within the United States, and outline future perspectives and novel device in development.

Association of pre–left ventricular assist device defibrillator shocks for ventricular arrhythmia with clinical outcomes after left ventricular assist device implantation

Implantable cardioverter-defibrillation (ICD) shocks after left ventricular assist device therapy (LVAD) are associated with adverse clinical outcomes. Little is known about the association of pre-LVAD ICD shocks on post-LVAD clinical outcomes and whether LVAD therapy affects the prevalence of ICD shocks. The purpose of this study was to determine whether pre-LVAD ICD shocks are associated with adverse clinical outcomes post-LVAD and to compare the prevalence of ICD shocks before and after LVAD therapy. Patients 18 years or older with continuous-flow LVADs and ICDs were retrospectively identified within the University of Pittsburgh Medical Center system from 2006-2020. We analyzed the association between appropriate ICD shocks within 1 year pre-LVAD with a primary composite outcome of death, stroke, and pump thrombosis and secondary outcomes of post-LVAD ICD shocks and ICD shock hospitalizations. Among 309 individuals, average age was 57 ± 12 years, 87% were male, 80% had ischemic cardiomyopathy, and 42% were bridge to transplantation. Seventy-one patients (23%) experienced pre-LVAD shocks, and 69 (22%) experienced post-LVAD shocks. The overall prevalence of shocks pre-LVAD and post-LVAD were not different. Pre-LVAD ICD shocks were not associated with the composite outcome. Pre-LVAD ICD shocks were found to predict post-LVAD shocks (hazard ratio [HR] 5.7; 95% confidence interval [CI] 3.42-9.48; P <.0001) and hospitalizations related to ICD shocks from ventricular arrhythmia (HR 10.34; 95% CI 4.1-25.7; P <.0001). Pre-LVAD ICD shocks predicted post-LVAD ICD shocks and hospitalizations but were not associated with the composite outcome of death, pump thrombosis, or stroke at 1 year. The prevalence of appropriate ICD shocks was similar before and after LVAD implantation in the entire cohort.

Long-Term Medical Treatment and Adherence in Patients With Left Ventricular Assist Devices: A Danish Nationwide Cohort Study.

The use of a left ventricular assist device (LVAD) in treating advanced heart failure has increased. However, data regarding medical treatment and adherence following LVAD implantation is sparse, particularly whether socioeconomic factors (cohabitation status, educational level, employment status, and income) and multimorbidity influence these aspects, which are known to impact adherence in heart failure patients. We performed a nationwide cohort study of 119 patients with LVAD implanted between January 1, 2006, and December 31, 2018, who were discharged alive with LVAD therapy. We linked individual-level data from clinical LVAD databases, the Scandiatransplant Database, and Danish medical and administrative registers. Medical treatment 90-day pre-LVAD and 720-day post-LVAD were assessed using descriptive statistics in 90-day intervals. Medication adherence (proportion of days covered ≥80%) was assessed 181- to 720-day post-LVAD. The proportions of patients using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (88.7%), beta-blockers (67.0%), mineralocorticoid receptor antagonists (62.9%), warfarin (87.6%), and aspirin (55.7%) within 90-day post-LVAD were higher than pre-LVAD and were stable during follow-up. Medication adherence ranged from 86.7% (aspirin) to 97.8% (warfarin). Socioeconomic factors and multimorbidity did not influence medical medication use and adherence. Among LVAD patients, medical treatment and adherence are at high levels, regardless of socioeconomic background and multimorbidity.

Changing Strategy Between Bridge to Transplant and Destination LVAD Therapy After the First 3 Months: Analysis of the STS-INTERMACS Database

Background: Left ventricular assist devices (LVADs) have been implanted as bridge to transplantation (BTT), bridge to candidacy (BTC) or destination therapy (DT) based on relative and absolute contraindications to transplantation. Multiple factors may lead to change in the strategy of support after LVAD implantation. Methods: From INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) 2012-2020, 11,262 patients survived to 3 months on continuous flow LVADs with intent of BTT or DT. Pre-implant characteristics and early events post-LVAD were analyzed in relation to changes in BTT or DT strategy during the next 12 months. Results: Among 3216 BTT patients at 3 months, later transplant de-listing or death without transplant occurred in 536 (16.7%) and, was more common with age, Profiles 1-2, renal dysfunction, and independently for prior cardiac surgery (HR 1.25, 95% CI 1.04-1.51, p = 0.02). Post-LVAD events of infections, gastrointestinal bleeding, stroke, and right heart failure defined by inotropic therapy predicted de-listing and death, as did in-hospital location at 3 months (HR 1.67, 95% CI 1.20-2.33, p =0.0024). Of 8046 patients surviving to 3 months with intent as destination therapy, 750 (9.3%) subsequently underwent listing or transplant, often with initial history of acute HF (HR 1.70, 95% CI 1.27-2.27, p = 0.0012) or malnutrition-cachexia (1.73, 95% CI 1.14-2.63, p = 0.0099). Multiple gastrointestinal bleeding events (≥4) with LVAD increased transition from BTT to DT (HR 4.22, 95% CI 1.46-12.275, p = 0.0078) but also from DT to BTT (HR 5.17, 95% CI 1.92-13.9, p = 0.0011). Conclusions: Implant strategies change over time in relation to pre-implant characteristics and adverse events post implant. Pre-implant recognition of factors predicting later change in implant strategy will refine initial triage, while further reduction of post-LVAD complications will expand options including eventual consideration of heart transplant.

Assessment of Autophagy Markers Suggests Increased Activity Following LVAD Therapy

Left ventricular reverse remodeling in heart failure is associated with improved clinical outcomes. However, the molecular features that drive this process are poorly defined. Left ventricular assist devices (LVADs) are the therapy associated with the greatest reverse remodeling and lead to partial myocardial recovery in most patients. In this study, we examined whether autophagy may be implicated in post-LVAD reverse remodeling. We found expression of key autophagy factors increased post-LVAD, while autophagic substrates decreased. Autolysosome numbers increased post-LVAD, further indicating increased autophagy. These findings support the conclusion that mechanical unloading activates autophagy, which may underly the reverse remodeling observed.

Considerations of Left Ventricular Assist Device Therapy in the United States’ Prison System

Left ventricular assist device therapy for advanced heart failure is contraindicated if a patient lives in an unsafe environment and recent guidelines declare that “legal history is pertinent for determining personal constraints or financial responsibilities due to parole requirements, pending charges, and possible imprisonment,” implying that incarceration would be a contraindication. International guidelines and precedent in the United States establish that medical care for incarcerated persons should match access in the community. We present a case example and practical considerations for advanced heart failure programs faced with the challenge of partnering with patients with heart failure who may be incarcerated and their correctional health systems in the care of their chronic condition. We encourage the heart failure community to not let incarceration be a contraindication to left ventricular assist device therapy.

LVAD therapy as a catalyst to heart failure remission and myocardial recovery.

The management of chronic heart failure over the past decade has witnessed tremendous strides in medical optimization and device therapy including the use of left ventricular assist devices (LVAD). What we once thought of as irreversible damage to the myocardium is now demonstrating signs of reverse remodeling and recovery. Myocardial recovery on the structural, molecular, and hemodynamic level is necessary for sufficient recovery to withstand explant and achieve sustained recovery post-LVAD. Guideline-directed medical therapy and unloading have been shown to aid in recovery with the potential to successfully explant the LVAD. This review will summarize medical optimization, assessment for recovery, explant methodologies and outcomes post-recovery with explant of durable LVAD.

Long-term medical treatment and adherence in patients with left ventricular assist devices: a Danish nationwide cohort study

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Grant from Karen Elise Jensen Foundation and Helse Foundation. Introduction An increasing number of patients with advanced heart failure (HF) live with a left ventricular assist device (LVAD). Data regarding medical treatment after LVAD implantation is sparse, including the impact of socioeconomic factors and multimorbidity. Purpose To describe medication use and assess the influence of socioeconomic factors and multimorbidity on medication use in the first two years following LVAD implant. Methods We conducted a nationwide cohort study based on data from the Danish clinical LVAD databases, the Scandiatransplant Database, and Danish nationwide administrative and medical registries. We identified patients with LVAD implantation between January 1, 2008, and December 31, 2018, who were discharged with LVAD therapy. Patients were followed until heart transplantation, LVAD explant, death, or December 31, 2018. Medication use was defined as a redeemed prescription from the Danish National Prescription Registry using ATC codes. Socioeconomic factors included cohabitation status, highest education attained, employment status, and personal income. Multimorbidity was defined as two or more chronic conditions. Medical treatment 90 days before LVAD implant and 720 days post-LVAD were assessed using descriptive statistics in 90 days intervals. Results We identified 119 patients; 88.2% were male, and the mean age (standard deviation) was 52.6 (14.5) years. The median (IQR) follow-up time was 0.8 years (0.4;1.8 years). 44.5% of patients underwent heart transplantation, and 4.2% had the LVAD explanted during follow-up. 27.7% of the patients were living alone, 27.7% had a low educational level, 37.8% were unemployed, 15.1% were in the lowest income (25 percentile), and 16.8% were categorized with multimorbidity (without cardiovascular disease group). The proportion of medication users of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (88.7%), beta-blocker (67%), mineralocorticoid receptor antagonists (62.9%), warfarin (87.6%), and aspirin (55.7%) within 90 days post-LVAD were substantially higher than pre-LVAD and were stable during the follow-up (Figure 1). In contrast, the proportion of diuretic users was lower post-LVAD implant than pre-LVAD, decreased further, and plateaued up to 180 days after hospital discharge. Stratified analyses according to socioeconomic factors and multimorbidity showed no differences in medication use (Figure 2). Conclusions Guideline-derived medical therapies for HF increased after LVAD implantation and were stable during long-term follow-up. As expected, the proportion of warfarin users increased substantially after LVAD implantation. Surprisingly, the percentage of aspirin users was not at the same level as for warfarin users. Socioeconomic factors and comorbidity burden did not influence long-term medication use of guideline-derived HF therapies, warfarin and aspirin in LVAD recipients.

Gastrointestinal bleeding on continuous-flow left ventricular assist device therapy.

While technological advances in the field of continuous-flow left ventricular assist device (CF-LVAD) are constantly being made, CF-LVAD recipients are still subjected to a relatively high rate of LVAD-related adverse events, with post-LVAD gastrointestinal bleeding (GIB) being the most common one. GIB is associated with a significant impairment in quality of life, multiple hospital admissions, blood transfusion requirements and possibly death. Furthermore, of those patients who bled once, many will experience recurrent GIB events, which further aggravates their discomfort. While some medical and endoscopic treatment options are available, evidence regarding their benefit remains largely equivocal, with all related studies based on data from registries rather than clinical trials. Although having a major impact on LVAD recipients, an effective and validated pre-implant screening options to predict GIB events post-implant are scarce. This review focuses on the aetiology, incidence, risk factors, treatment options and the effect of new generation devices on post-LVAD GIB.

P80: Adding Intra-Aortic Balloon Pump Counter-Pulsation To Vasodilator Therapy Results In Better Organ Perfusion In Patients With Biventricular Heart Failure Awaiting A Heart Transplant

Background: Significant right ventricular dysfunction with elevated central venous pressure is associated with poor survival in heart failure patients with reduced ejection fraction (HFrEF). Heart transplant is often the only option for this group of patients, as they are not candidates for left ventricular assist device therapy. Medical management of HFrEF involves lowering the systemic afterload with vasodilators. While this therapy is very effective in isolated left ventricular dysfunction, in patients with biventricular dysfunction and high venous pressure, vasodilation can lead to low organ perfusion pressure, resulting in organ dysfunction. Organ perfusion pressure is calculated as the difference between mean arterial pressure and central venous pressure. We hypothesized that combining intra-aortic balloon pump (IABP) counter-pulsation with vasodilator therapy might be a good clinical option for stabilizing these patients while awaiting a heart transplant. Methods: To understand the hemodynamics of vasodilator and IABP therapy in biventricular heart failure, we used a closed-loop multiscale model of the entire cardiovascular system, including a one-dimensional model of the arterial tree coupled with a lumped model of the heart and IABP counter-pulsation. In addition, a baroreceptor model was also used to capture the physiological changes secondary to ventricular dysfunction realistically. Results: Our mathematical model accurately captures the features of the aortic pressure waveform with IABP support (Figure 1) and the hemodynamic consequences of the onset of right ventricular dysfunction (Table 1). Biventricular dysfunction leads to lower cardiac output and organ perfusion pressure when compared with isolated left ventricular dysfunction. Vasodilation during biventricular dysfunction increases the cardiac output but reduces the organ perfusion pressure further. IABP counter-pulsation increases cardiac output along with higher mean arterial pressure and hence higher organ perfusion pressure. The best results are seen when vasodilators are used in conjunction with IABP, where a “sweet spot” of maximal increase in cardiac output with the best possible organ perfusion pressure is obtained, and this combined additive effect of IABP counter-pulsation and vasodilation is also reflected across the renal vasculature (Table 1). Conclusion: Vasodilation with high venous pressure can lead to low organ perfusion pressure and consequent organ dysfunction. Fine-tuning IABP counter-pulsation and vasodilator seems to confer a substantial hemodynamic benefit in this setting.Figure 1. Simulated aortic pressure waveform with IABP support

Predictors and clinical implications of residual mitral regurgitation following left ventricular assist device therapy

BackgroundCorrection of mitral regurgitation (MR) at the time of left ventricular assist device (LVAD) implantation remains controversial. There is conflicting evidence regarding the clinical impact of residual MR, and studies...

CARC19: An Updated Analysis of the Impact of U.S. Heart Transplantation Allocation System Change on LVAD Patients

Background: On 10/18/2018, a substantial U.S. heart transplantation (HT) allocation system change (ASC) became effective, resulting in lower priority for left ventricular assist device (LVAD) patients. While previous preliminary analyses demonstrated worse post-HT survival among LVAD patients between different eras, it remains unclear whether the presence of LVAD independently predicts unfavorable outcomes within the post-ASC period, especially among patients with expected longer wait times. Methods: Two cohorts of adult patients from the UNOS database were included, and their 1-year outcomes were analyzed. The pre-ASC and post-ASC cohorts encompassed patients listed between 10/18/2014 to 10/18/2017 and 10/18/2018 to 10/18/2021, respectively. We excluded patients listed before and transplanted after ASC. Cox regression models and competing risk analysis were performed. Results: 17,923 patients (post-ASC=9,684) were included (26.7% females, mean age of 53.4±12.5 years old). 3,873 had an LVAD (post-ASC=1,958), of which 3,003 underwent HT (post-ASC=1,515). Compared to LVAD patients transplanted in the pre-ASC era, those in the post-ASC era had shorter waitlist time; however, their grafts traveled longer distances with more prolonged ischemic time. After adjustment for potential confounders, LVAD was associated with a lower risk of waitlist mortality in both the pre- and post-ASC periods. Moreover, LVAD was associated with a lower HT rate (HR 0.74, 95% CI 0.70-0.79, p<0.001) and higher one-year post-HT mortality (HR 1.53, 95% CI 1.27-1.84, p<0.001) than those without long-term devices in the post-ASC. Notably, these differences were not observed in the pre-ASC. The association between LVAD and higher post-HT mortality was no longer seen after adjustment for the effect modification by ASC. Conclusions: Our findings suggest that LVAD therapy saves patients’ lives while waiting for HT. However, the ASC brought several changes to practice, which might be associated with increased post-HT mortality observed in patients bridged with LVAD. Further studies are needed to identify the highest-risk subgroups among LVAD patients to promote equity in donor organ allocation.

Diabetes mellitus impact on left ventricular assist deviceoutcomes in heart failure patients: National Inpatient Sample study.

Aim: Diabetes mellitus (DM) is a recognized risk factor for heart failure (HF), increasing the likelihood of requiring left ventricular assist device (LVAD) therapy. Objective: This retrospective cohort study aims to assess the impact of DM on LVAD patients, focusing on in-hospital mortality as the primary outcome. Methods: Utilizing the National Inpatient Sample administrative database, data from 11,506 adult HF patients who underwent LVAD implantation were analyzed. Results: Of the patients, 44.28% had diabetes. Adjusting for various factors, diabetic patients exhibited shorter hospital stays, lower admission costs and similar in-hospital mortality rates compared with non-diabetic patients. Conclusion: These findings enhance our understanding of the risks and benefits of LVAD therapy in patients with refractory HF and DM.